/*
 * Copyright (c) 2002-2008 Gargoyle Software Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.gargoylesoftware.htmlunit.javascript.host;

import java.io.IOException;
import java.net.URL;
import java.util.Collections;
import java.util.List;

import org.apache.commons.httpclient.HttpStatus;
import org.apache.commons.httpclient.NameValuePair;
import org.mozilla.javascript.Context;

import com.gargoylesoftware.htmlunit.HttpMethod;
import com.gargoylesoftware.htmlunit.WebRequestSettings;
import com.gargoylesoftware.htmlunit.WebResponse;
import com.gargoylesoftware.htmlunit.WebResponseData;
import com.gargoylesoftware.htmlunit.WebResponseImpl;
import com.gargoylesoftware.htmlunit.WebWindow;
import com.gargoylesoftware.htmlunit.html.DomAttr;
import com.gargoylesoftware.htmlunit.html.DomCData;
import com.gargoylesoftware.htmlunit.html.DomComment;
import com.gargoylesoftware.htmlunit.html.DomElement;
import com.gargoylesoftware.htmlunit.html.DomNode;
import com.gargoylesoftware.htmlunit.html.DomText;
import com.gargoylesoftware.htmlunit.html.HtmlElement;
import com.gargoylesoftware.htmlunit.html.HtmlPage;
import com.gargoylesoftware.htmlunit.javascript.SimpleScriptable;
import com.gargoylesoftware.htmlunit.xml.XmlElement;
import com.gargoylesoftware.htmlunit.xml.XmlPage;

/**
 * A JavaScript object for XMLDocument.
 *
 * @version $Revision$
 * @author Ahmed Ashour
 * @author Marc Guillemot
 * @author Sudhan Moghe
 */
public class XMLDocument extends Document {

    private static final long serialVersionUID = 1225601711396578064L;
    private boolean async_ = true;
    private boolean preserveWhiteSpace_;
    private XMLDOMParseError parseError_;

    /**
     * Creates a new instance. JavaScript objects must have a default constructor.
     */
    public XMLDocument() {
        this(null);
    }

    /**
     * Creates a new instance, with associated XmlPage.
     * @param enclosingWindow
     */
    XMLDocument(final WebWindow enclosingWindow) {
        if (enclosingWindow != null) {
            try {
                final XmlPage page = new XmlPage((WebResponse) null, enclosingWindow);
                setDomNode(page);
            }
            catch (final IOException e) {
                throw Context.reportRuntimeError("IOException: " + e);
            }
        }
    }

    /**
     * Sets the <tt>async</tt> attribute.
     * @param async Whether or not to send the request to the server asynchronously
     */
    public void jsxSet_async(final boolean async) {
        this.async_ = async;
    }

    /**
     * Returns Whether or not to send the request to the server asynchronously.
     * @return the <tt>async</tt> attribute
     */
    public boolean jsxGet_async() {
        return async_;
    }

    /**
     * Loads an XML document from the specified location.
     *
     * @param xmlSrouce a string containing a URL that specifies the location of the XML file
     * @return true if the load succeeded; false if the load failed
     */
    public boolean jsxFunction_load(final String xmlSrouce) {
        if (async_) {
            getLog().debug("XMLDocument.load(): 'async' is true, currently treated as false.");
        }
        try {
            final HtmlPage htmlPage = (HtmlPage) getWindow().getWebWindow().getEnclosedPage();
            final WebRequestSettings settings = new WebRequestSettings(htmlPage.getFullyQualifiedUrl(xmlSrouce));
            final WebResponse webResponse = getWindow().getWebWindow().getWebClient().loadWebResponse(settings);
            final XmlPage page = new XmlPage(webResponse, getWindow().getWebWindow(), false);
            setDomNode(page);
            return true;
        }
        catch (final IOException e) {
            final XMLDOMParseError parseError = jsxGet_parseError();
            parseError.setErrorCode(-1);
            parseError.setFilepos(1);
            parseError.setLine(1);
            parseError.setLinepos(1);
            parseError.setReason(e.getMessage());
            parseError.setSrcText("xml");
            parseError.setUrl(xmlSrouce);
            getLog().debug("Error parsing XML from '" + xmlSrouce + "'", e);
            return false;
        }
    }

    /**
     * Loads an XML document using the supplied string.
     *
     * @param strXML A string containing the XML string to load into this XML document object
     *        This string can contain an entire XML document or a well-formed fragment.
     * @return true if the load succeeded; false if the load failed
     */
    public boolean jsxFunction_loadXML(final String strXML) {
        try {
            final List<NameValuePair> emptyList = Collections.emptyList();
            final WebResponseData data = new WebResponseData(strXML.getBytes(), HttpStatus.SC_OK, null, emptyList);
            final WebResponse webResponse = new WebResponseImpl(data, (URL) null, (HttpMethod) null, 0);
            final XmlPage page = new XmlPage(webResponse, getWindow().getWebWindow());
            setDomNode(page);
            return true;
        }
        catch (final IOException e) {
            getLog().debug("Error parsing XML\n" + strXML, e);
            return false;
        }
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public SimpleScriptable makeScriptableFor(final DomNode domNode) {
        final SimpleScriptable scriptable;

        // TODO: cleanup, getScriptObject() should be used!!!
        if (domNode instanceof XmlElement) {
            scriptable = new XMLElement();
        }
        else if (domNode instanceof DomAttr) {
            final XMLAttr attribute = new XMLAttr();
            attribute.init(domNode.getNodeName(), (DomElement) domNode.getParentNode());
            scriptable = attribute;
        }
        else if (domNode instanceof DomText || domNode instanceof DomCData || domNode instanceof DomComment) {
            scriptable = new TextImpl();
        }
        else {
            scriptable = super.makeScriptableFor(domNode);
        }

        scriptable.setPrototype(getPrototype(scriptable.getClass()));
        scriptable.setParentScope(getParentScope());
        scriptable.setDomNode(domNode);
        return scriptable;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    protected void initParentScope(final DomNode domNode, final SimpleScriptable scriptable) {
        scriptable.setParentScope(getParentScope());
    }

    /**
     * Gets the JavaScript property "parseError" for the document.
     * @return the ParserError object for the document
     */
    public XMLDOMParseError jsxGet_parseError() {
        if (parseError_ == null) {
            parseError_ = new XMLDOMParseError();
            parseError_.setPrototype(getPrototype(parseError_.getClass()));
            parseError_.setParentScope(getParentScope());
        }
        return parseError_;
    }

    /**
     * Contains the XML representation of the node and all its descendants.
     * @return an XML representation of this node and all its descendants
     */
    public String jsxGet_xml() {
        final XMLSerializer seralizer = new XMLSerializer();
        seralizer.setParentScope(getWindow());
        seralizer.setPrototype(getPrototype(seralizer.getClass()));
        return seralizer.jsxFunction_serializeToString((Node) jsxGet_documentElement());
    }

    /**
     * Gets the current white space handling.
     * @return the current white space handling
     */
    public boolean jsxGet_preserveWhiteSpace() {
        return preserveWhiteSpace_;
    }

    /**
     * Specifies the white space handling.
     * @param preserveWhiteSpace white space handling
     */
    public void jsxSet_preserveWhiteSpace(final boolean preserveWhiteSpace) {
        this.preserveWhiteSpace_ = preserveWhiteSpace;
    }

    /**
     * This method is used to set
     * <a href="http://msdn2.microsoft.com/en-us/library/ms766391.aspx">second-level properties</a>
     * on the DOM object.
     *
     * @param name the name of the property to be set
     * @param value the value of the specified property
     */
    public void jsxFunction_setProperty(final String name, final String value) {
        //empty implementation
    }

    /**
     * Applies the specified XPath expression to this node's context and returns the generated list of matching nodes.
     * @param expression a string specifying an XPath expression
     * @return list of the found elements
     */
    public HTMLCollection jsxFunction_selectNodes(final String expression) {
        final HTMLCollection collection = new HTMLCollection(this);
        collection.init(getDomNodeOrDie(), expression);
        return collection;
    }

    /**
     * Applies the specified pattern-matching operation to this node's context and returns the first matching node.
     * @param expression a string specifying an XPath expression
     * @return the first node that matches the given pattern-matching operation
     *         If no nodes match the expression, returns a null value.
     */
    public Object jsxFunction_selectSingleNode(final String expression) {
        final HTMLCollection collection = jsxFunction_selectNodes(expression);
        if (collection.jsxGet_length() > 0) {
            return collection.get(0, collection);
        }
        return null;
    }

    /**
     * Returns all the descendant elements with the specified tag name.
     * @param tagName the name to search for
     * @return all the descendant elements with the specified tag name
     */
    public HTMLCollection jsxFunction_getElementsByTagName(final String tagName) {
        final HTMLCollection collection = new HTMLCollection(this);
        collection.init(getDomNodeOrDie().getFirstChild(), "//" + tagName);
        return collection;
    }

    /**
     * {@inheritDoc}
     */
    public Object jsxFunction_getElementById(final String id) {
        final XmlPage xmlPage = (XmlPage) getDomNodeOrDie();
        final Object domElement = xmlPage.getFirstByXPath("//*[@id = \"" + id + "\"]");
        if (domElement == null) {
            return null;
        }

        if (domElement instanceof HtmlElement) {
            return ((HtmlElement) domElement).getScriptObject();
        }
        getLog().debug("getElementById(" + id + "): no HTML DOM node found with this id");
        return null;
    }
}